Basic Wheel Info

Rim Diameter - is the distance measured from the upper and lower tire bead seat. It is NOT the overall diameter of the wheel.

Rim Width- is the distance from the inner and outer tire bead seat. It is NOT the overall width of the wheel.

Offset - is the distance in Millimeters positive of negative from the center of the wheel to the wheels mounting surface.

Backspacing - is the distance from the wheels mounting surface to the bead seat on the back of the wheel.

Bolt Circle (PCD) - is the number of holes on the mounting surface and their distance from one and other.

Lugs (lug nuts, lug bolts) - Nuts or Bolts used to secure a wheel to an automobiles hub.

Hub Bore - the hole on the back of the wheel that is machined to clear the hub of the car.

Determining Your Bolt Pattern (PCD)

For 4, 6, 8 Lug Applications

Measure from the hole from middle to the middle of the opposite hole

For 5 Lug Applications

Measure from the Middle of a hole to the end of the second hole from it

How to find Offset

Formula: Backspace - ( Width / 2 ) To Convert into Millimeters multiply by 25.4

Also Can be Defined as the distance from the Centerline of the wheel to the mounting surface(mounting pad).

What This Means

Positive Offset - Means the wheel will tuck under the car more.

Zer0 Offset - The wheel will stretch the same distance in and out from the mounting surface.

Negative Offset - Means the wheel will sit further away from the car.